The proposed Mentored Research Scientist Development Award (K01) entitled 'Iyengar yoga for adolescents and young adults with irritable bowel syndrome' is a first resubmission in response to PA-09-040 (previously PA-06-001). The proposed training and research will take place in the Pediatric Pain Program (PPP) within the David Geffen School of Medicine at the University of California, Los Angeles, where I am currently serving as Assistant Researcher in the Faculty series. Immediate goals: After spending my PhD dissertation examining the impact of maternal chronic pain on children's psychosocial and pain development and a post-doctoral research fellowship at Brunel University in West London, my immediate goal is to apply biopsychosocial pain research to the understanding of mind- body medicine. I have a long-standing interest in mind-body techniques such as yoga and meditation, and intend to scientifically examine the benefits I have noted in my personal practice. To this end, I intend to conduct this first, preliminary study of yoga for adolescents and young adults with irritable bowel syndrome (IBS), a common functional neurovisceral disorder. Given that limited research exists regarding the safety, feasibility and efficacy of yoga for young people, I plan to conduct a randomized controlled trial (RCT) of yoga for young IBS patients using a standardized yoga intervention and a wait-list usual care control group, and explore biobehavioral mediator mechanisms. Long-term goals: My long-term goal is to become an independent investigator with expertise in biopsychosocial measures and the conduct of RCTs of mind-body interventions for pain management in children, young adults and families. My ultimate goal is to advance the field of complementary and alternative medicine (CAM) by delineating the physiological and psychospiritual mechanisms in the action of yoga upon clinical outcomes in pain. The training and research plan proposed in this application will enable me to begin a program of research that will implement a series of high quality, methodologically sound clinical trials on yoga to understand both mechanistic processes and key predictors of clinical outcomes to understand what works for whom and why. Training/Research Career Development: My career development plan includes courses in physiology, neuroendocrinology, advanced statistics, mind-body techniques and the responsible conduct of clinical research. My career development will also involve mentoring experiences with Dr Lonnie Zeltzer, an eminent pediatric CAM and pain researcher, Dr Bruce Naliboff, a thought leader in functional pain conditions and Dr Jennie Tsao, who has extensive experience in research design and data analysis for pain research. Environment: The PPP specifically and UCLA in general are both extremely supportive of biopsychosocial research. UCLA houses a number of centers and programs specializing in CAM which will support my development as a mind-body researcher. Moreover, the Department of Pediatrics has been very forthcoming about its support of my training and research plans. Research: IBS affects as many as 14% of high school-aged students. Symptoms include discomfort in the abdomen, along with diarrhea and/or constipation and other gastroenterological symptoms, which can significantly impact quality of life and daily functioning of patients. Emotional stress appears to exacerbate IBS symptoms suggesting that mind-body interventions reducing arousal may prove beneficial. For many sufferers, symptoms can be traced to childhood and adolescence, making the early manifestation of IBS important to understand. The current study will focus on young people aged 16-22 years with IBS. The study will test the potential benefits of Iyengar yoga (IY) on clinical symptoms, psychospiritual functioning and visceral sensitivity. Yoga is thought to bring physical, psychological and spiritual benefits to practitioners and has been associated with reduced stress and pain. Through its focus on restoration and use of props, IY is especially designed to decrease arousal and promote psychospiritual resources in physically compromised individuals. IY is suitable for research, as an extensive and standardized teacher-training program ensure it is replicable and safe. Sixty-four IBS patients aged 16-22 will be randomly assigned to a standardized 8-week biweekly IY group-based program (1.5 hour sessions) or a wait-list usual care control group. The groups will be compared on the primary clinical outcomes of IBS symptoms, quality of life and global improvement at post- treatment and 2 month follow-up. Secondary outcomes will include visceral pain sensitivity assessed with a standardized laboratory task (water load task), and psychospiritual variables including coping, self-efficacy, mood, acceptance and mindfulness. Mechanisms of action involved in the proposed beneficial effects of yoga upon clinical outcomes will be explored, and include the mediating effects of visceral sensitivity, increased psychospiritual resources, regulated autonomic nervous system (ANS) responses (measured in response to the visceral sensitivity task) and regulated hormonal stress response assessed via salivary cortisol. It is hypothesized that IY will be safe and feasible: with less than 20% attrition; and the IY group will demonstrate significantly improved outcomes compared to controls, with physiological and psychospiritual mechanisms contributing to improvements; clinical treatment gains will be maintained at 2 months following yoga.